" From 1781, by which time Goethe had been in Weimer for six years, he confided to Charlotte that he no longer felt able to address her as "Sie," and must use the more intimate "du." This brought about a sea change. As one critic put it, Goethe's letters now became "prose poems of happy love with few parallels in any literature. "

― Peter Watson , The German Genius: Europe's Third Renaissance, the Second Scientific Revolution, and the Twentieth Century